Metal-welding.



UNITED STATES PATENT OFFICE,

HEINRICH WACHWITZ, OF NUREMBERG, GERMANY.

METAL- WELDING,

SPECIFICATION forming part of Letters Patent N 0. 684,479, dated October15, 1901. Application filed Mtty 9, 1898. Serial No. 680,141. (Nospecimens.)

To all whom it may concern:

Be it known that I, HErNRIcH WAcHwrrz, asubject of the Emperor ofGermany, residing at Nuremberg, Bavaria, Germany, have invented certainnew and useful Improvements in Processes for Plating Aluminium Sheetswith Copper and other Metals, of which the following is a specification.

It has been found that plating aluminium with metals, and especiallycopper, by the usual process of heating or welding, an aluminium alloyis formed on the surface, which destroys the ductility of the coppercoatingsheet (where copper is used) and prevents a perfect union betweenthe aluminium plate and the coating metal where other metals than copperare used. The object of my invention is to overcome this twofolddifficulty, and I accomplish it in the following manner.

In plating aluminium with copper I first form on the surface of thecopper an alloy with zinc by coating the copper with said metal inliquid form and heating the coated plates and excluding the air duringsuch heating. When the zinc-copper alloy has been so formed on thecopper plates, the latter are hammered into thin sheets of aluminium inany suitable manner which will secure the firm application of the thinsheets of aluminium to or incorporated with the previously zinc treatedsurface of the copper plates. The compound plate thus formed-11 a, thezinc-treated copper plates incorporated with the thin aluminiumcoveringis then used to plate or coat the aluminium base, plate, orobject, the aluminium-covered surface of the copper plate being placedcontiguous to the aluminium base. This last step is performed byheating, rolling, and working in the manner described in United StatesLetters Patent flowtiim or by any method preferred.

\"Vheii'liietals other than copper are used to plate the aluminium, itis not necessary to use the zinc or form an alloy on the coatingbody;but the hammered application of the thin sheet of aluminium to thecoating-body preliminary to the regular plating by heat is essential andin all other respects, except as to the alloy, the process is the same.

It will be seen that my process ordinarily o involves two steps-onemechanical (the ham mering of the thin sheet of aluminium) and the otherchemical and mechanical (the heating, rolling, and working but when aplating of copper on aluminium is desired it involves threesteps-chemical, (forming an alloy on the surface of the copper plate,)mechanical, (hammering the thin sheets of aluminium on the copperplates,) and chemical and me chanical, (heating, rolling, and working.)66

Having thus described my invention, I claim and desire to obtain byLetters Patent- 1. The process of coating aluminium sheets with othermetals, consisting of applying to the surface of the coating metal by hing, a thin sheet or layer of aluminium, then applying said compoundsheet to the aluminium sheet or body to be coated, and heating, rollingand working the'same together.

2. The process of coating aluminium sheets 70 or bodies with sheets ofcopper consisting in forming a Zinc-copper alloy on the surface of thecopper sheet, hammering the latter into a thin sheet of aluminium, thenapplying said compound sheet to the aluminium body to be coated, andheating, rolling, and working the same together.

In testimony whereof I affix my signature in presence of two witnesses.

HEINRICH I WACII WITZ.

Witnesses:

ALEX WIELE, MAX SCHNEIDER.

